Intramolecular Palladium(II)-Catalyzed Regioselective 6-endo or 6-exo C-H Benzannulation: An Approach for the Diversity-Oriented Synthesis of Quinolinone Derivatives from Pyridones.

Herein, a new intramolecular palladium(II)-catalyzed regioselective 6-endo-trig or 6-exo-trig annulation through direct C-H activation is presented as a method for the diversity-oriented synthesis of highly substituted quinolinones from pyridones. The reaction occurs under mild conditions and exhibits excellent regioselectivity, good functional group tolerance, and broad applications. This innovative approach has been successfully utilized in the synthesis of Glycopentanolone A and an intermediate of (R)-(+)-Tipifarnib.

Photoinduced [3+2] Cycloaddition of Alkyl-Acceptor Diazoalkanes: Diversity-Oriented Synthesis of Pyrazolines Containing a Quaternary Center.

We present a new [3+2] cycloaddition reaction between alkyl-acceptor diazoalkanes under visible light irradiation. By employing easily accessible alkyl-acceptor-type diazoalkanes or their precursor hydrazones as both 1,3-dipoles and dipolarophiles, a diverse range of pyrazoline derivatives featuring a quaternary center have been efficiently synthesized in a predictable manner, with excellent functional group tolerance and good yields. Furthermore, scale-up experiments and downstream transformations of the product were also detailed.

Regioselective [2 + 1] photocycloaddition of 2-pyridones with diazo compounds.

Herein, we report a novel regioselective [2 + 1] cyclization reaction of 2-pyridones with carbenes generated in situ via visible light irradiation, without the requirement for catalysts or additives. The diverse functional groups of 2-pyridones and diazo compounds exhibit good tolerance, enabling the rapid synthesis of highly valuable cyclopropanated dihydro-2-pyridone scaffolds with exceptional regio- and stereoselectivity. Furthermore, DFT calculations provide a comprehensive explanation for the regio- and stereoselectivity observed in the reaction.

Maternal and Neonatal Outcomes After Planned or Emergency Delivery for Placenta Accreta Spectrum: A Systematic Review and Meta-Analysis.

Objective: To compare maternal and neonatal outcomes for women with placenta accreta syndrome (PAS) delivering via a planned or emergent approach. Methods: A systematic search for relevant studies was conducted by screening the PubMed, Scopus, Web of Science, and Google Scholar electronic databases. Included studies should have been retrospective record-based or prospective in design. They must have compared maternal and/or neonatal outcomes for PAS patients delivering via planned and emergency procedures. Strength of association was presented as pooled adjusted relative risk (RR) for categorical outcomes and weighted mean difference (WMD) for continuous outcomes. Statistical analysis was done using STATA version 16.0. Results: Nine articles were included in the meta-analysis. PAS patients undergoing planned deliveries had increased gestational ages, required fewer units of transfused blood, experienced shorter hospital stay durations, and presented reduced risks for maternal ICU admission and severe maternal morbidity. Neonates born to mothers undergoing planned deliveries had increased birth weights and decreased NICU admission risk. Conclusion: These findings indicate a planned approach for delivery is better for maternal and neonatal outcomes compared to urgent/emergency delivery for PAS patients.